1. Field of the Invention
The invention relates to a method and device for controlling a fan, more particularly to a method and device for controlling a heat-dissipating fan for an electronic component.
2. Description of the Related Art
Since electronic components tend to generate a lot of heat during operation, a cooling mechanism is required to ensure stable operation of electronic components. Referring to FIG. 1, a conventional cooling device 9 for a central processing unit (CPU) 90 used in a computer system is shown to include a fan controller 91 and a heat-dissipating fan 92. The fan controller 91 includes a computing unit 911 and a rotation speed control unit 912.
In operation, the central processing unit 90 outputs a temperature-sensing signal 901 to the computing unit 911 of the fan controller 91. The computing unit 911 detects a present temperature of the central processing unit 90 from the temperature-sensing signal 901. Thereafter, through a built-in algorithm, the computing unit 911 commands the rotation speed control unit 912 to output a driving signal 902 for controlling a rotating speed of the heat-dissipating fan 92. Accordingly, when the detected temperature is too high, the heat-dissipating fan 92 is driven to increase the rotating speed thereof. On the other hand, when the detected temperature is stable, the heat-dissipating fan 92 is driven to gradually reduce the rotating speed thereof. In the meantime, the heat-dissipating fan 92 outputs a feedback signal 903 to the computing unit 911. Therefore, the computing unit 911 can perform calculations according to the feedback signal 903 to permit driving of the heat-dissipating fan 92 for generating a stable air stream to cool down the central processing unit 90.
However, current methods of fan control are based on a state where the central processing unit 90 already generates heat, i.e., the resultant heat or temperature is calculated in the current methods. The current methods are unable to predict heat to be generated by the system for preemptive control of the fan so as to prevent overheating of electronic components from occurring.